Hydrogen Sulfide (H2S) Mitigates Sepsis-Induced Adrenal Dysfunction via Inhibition of TNFα-Mediated Necroptosis
Abstract
Background: Sepsis is a life-threatening condition that is characterized by systemic inflammation and organ dysfunction, with adrenal dysfunction being a significant complication. This study aimed to investigate the role of necroptosis and hydrogen sulfide (H2S) in sepsis-induced adrenal dysfunction.
Methods: A cecal ligation and puncture (CLP)-induced sepsis mouse model was employed. Adrenocortical-specific mixed lineage kinase domain-like pseudokinase (MLKL) knockout (MLKL-KO) and cystathioneine β-synthase (CBS) knockout (CBS-KO) mice were generated using Cre-loxP technology and adrenocortical-specific Cre tool mice. In vitro experiments utilized TNFα-stimulated Y1 adrenocortical cells. The treatments included the H2S donor NaHS, TNFα inhibitor R-7050, necroptosis inhibitor NSA and CBS inhibitor AOAA. Pathological assessment involved hematoxylin-eosin (H&E) staining and a Western blot analysis of necroptosis markers (the phosphorylation of MLKL (p-MLKL) and phosphorylation of receptor-interacting protein kinases 1 (p-RIPK1)).
Results: Sepsis induced adrenal congestion, elevated TNFα levels, and activated necroptosis (increased p-MLKL/p-RIPK1) in wild-type mice. H2S treatment attenuated adrenal damage, reduced TNFα, and suppressed necroptosis. MLKL knockout reduced septic adrenal dysfunction, whereas CBS knockout exacerbated septic adrenal dysfunction. In vitro, TNFα induced Y1 cell necroptosis, which was reversed by H2S or NSA. AOAA exacerbated TNFα-induced necroptosis in Y1 cells.
Conclusions: H2S inhibits TNFα-mediated necroptosis, thereby preserving adrenal integrity in sepsis. Targeting the TNFα-necroptosis axis and enhancing endogenous H2S production may represent novel therapeutic strategies for sepsis-associated adrenal dysfunction.